EP3699241A1 - Intumescent composition on epoxid basis having improved mechanical properties and its use - Google Patents

Abstract

An intumescent composition is described which contains an epoxy-based binder. The composition according to the invention, the mechanical resistance of which is relatively high, enables coatings to be applied in a simple and rapid manner, the coating withstanding high mechanical stress after curing. The composition according to the invention is particularly suitable for fire protection, in particular as a coating of metallic and non-metallic substrates, for example steel components, such as supports, girders, framework bars, to increase the fire resistance period.

Description

The present invention relates to an intumescent composition with improved mechanical properties, which contains a binder based on an epoxy resin, and its use for fire protection, in particular for coatings of components such as supports, girders, or framework bars, to increase the fire resistance period.

Intumescent compositions, also known as intumescent compositions, are usually applied to the surface of components to form coatings in order to protect them from fire or from the effects of great heat, for example as a result of a fire. Steel structures are now an integral part of modern architecture, even if they have a decisive disadvantage compared to reinforced concrete construction. Above approx. 500 ° C the load-bearing capacity of the steel drops by 50%, ie the steel loses its stability and its load-bearing capacity. Depending on the fire exposure, for example in the event of direct fire exposure (approx. 1000 ° C), this temperature can be reached after approx. 5-10 minutes, which often leads to a loss of load-bearing capacity of the construction. The objective of fire protection, especially steel fire protection, is now to delay the period of time until a steel structure loses its load-bearing capacity in the event of a fire in order to save human life and valuable goods.

In the building codes of many countries, corresponding fire resistance times are required for certain steel structures. They are defined by so-called F classes such as F 30, F 60, F 90 (fire resistance classes according to DIN 4102-2) or American classes according to ASTM, etc. According to DIN 4102-2, for example, F 30 means that a load-bearing steel structure must withstand the fire for at least 30 minutes under standard conditions in the event of a fire. This is usually achieved by slowing down the heating rate of the steel, e.g. B. by covering the steel structure with intumescent coatings. These are paints, the components of which foam up in the event of a fire, forming a solid, microporous carbon foam. A fine-pored and thick foam layer is formed, the so-called ash crust, which, depending on its composition, is highly heat-insulating and thus delays the heating of the component, so that the critical temperature of approx. 500 ° C, at the earliest after 30, 60, 90, 120 minutes or up to 240 minutes is achieved. The applied layer thickness of the coating or the resulting ash crust is essential for the achievable fire resistance. Closed profiles, such as pipes, require roughly twice the amount compared to open profiles, such as beams with a double-T profile, with comparable solidity. In order for the required fire resistance times to be met, the coatings must have a certain thickness and be able to form an ash crust that is as voluminous as possible and therefore well insulating when exposed to heat, which remains mechanically stable over the period of fire exposure.

Various systems exist for this in the prior art. Essentially, a distinction is made between 100% systems and solvent or water-based systems. In solvent or water-based systems, binders, usually resins, are applied to the component as a solution, dispersion or emulsion. These can be designed as single or multi-component systems. After application, the solvent or water evaporates and leaves a film that dries over time. A distinction can also be made between systems in which the coating essentially no longer changes during drying and systems in which, after evaporation, the binder hardens primarily through oxidation and polymerization reactions, which is induced, for example, by atmospheric oxygen becomes. The 100% systems contain the components of the binder without solvents or water. They are applied to the component, with the "drying" of the coating only taking place through the reaction of the binder components with one another, so-called reactive systems. Such an epoxy-based system is for example from EP 2935475 A1 known. Very similar systems with different binders are from the DE 102006056403 A1 , EP 2935476 A1 , EP 3176232 A1 , EP 1355054 A1 , DE 102012221451 A1 , EP 2955209 A1 , EP 2935470 A1 , EP 2935469 A1 , EP 2810970 A1 and EP3029129 A1 known.

These reactive systems have the disadvantage that the properties of the resulting protective layers with regard to mechanical stress (pressure, impact, abrasion) and viscoelastic properties (elastic and plastic deformation) are not ideally adapted to the application.

This can lead to the hardened coating being damaged, in which cracks appear or the coating even flakes off or flakes off in certain areas. The damaged coating can then no longer fully fulfill its function, such as an attractive appearance, protecting the coated substrates from corrosion or against the effects of heat, or ensuring air and water tightness.

In order to counter this problem, a great deal of effort is made to either protect the coated substrates from mechanical stress, for example by subsequent cladding or the like, or to subsequently repair the damage. However, these measures are costly and time-consuming and do not always lead to the desired result.

The invention is therefore based on the object of providing an intumescent composition for coating systems of the type mentioned at the outset which, after curing, has improved mechanical properties, which in particular results in a robust coating that simultaneously retains its elasticity and withstands mechanical stress without the coating Takes damage.

This object is achieved by the composition according to claim 1. Preferred embodiments can be found in the subclaims.

The invention accordingly relates to an intumescent composition which comprises an epoxy resin, an acid generator and water-soluble alkali metal silicates.

The composition according to the invention enables coatings to be obtained in a simple and rapid manner which, compared to the previously known coatings, have improved mechanical properties, which in particular withstand mechanical stress, without the coating being damaged and by which additional measures to protect the coating are dispensed with can.

• bedeutet "multifunktionell", dass die entsprechende Verbindung mehr als eine funktionelle Gruppe pro Molekül aufweist; dementsprechend bedeutet multifunktionell im Zusammenhang mit Epoxidverbindungen, dass diese mehr als eine Epoxidgruppen pro Molekül aufweisen, und in Bezug auf etwa Thiol-funktionalisierte Verbindungen, dass diese wenigstens zwei Thiolgruppen (-SH) pro Molekül aufweisen und in Bezug auf etwa Amin-funktionalisierte Verbindungen, dass diese wenigstens zwei Amingruppen (-NR₃) pro Molekül aufweisen; die Gesamtzahl der jeweiligen funktionellen Gruppen ist die Funktionalität der entsprechenden Verbindung;
• bedeutet "Gerüst" des Epoxidharzes oder der Thiol-funktionalisierten Verbindung der jeweils andere Teil des Moleküls, an das die funktionelle Epoxid- oder Thiolgruppe angebunden sein kann;
• bedeutet "chemische Intumeszenz" die Bildung einer voluminösen, isolierenden Ascheschicht durch aufeinander abgestimmte Verbindungen, die bei Hitzeeinwirkung miteinander reagieren;
• bedeutet "physikalische Intumeszenz" die Bildung einer voluminösen, isolierenden Schicht durch Aufblähen einer Verbindung, die, ohne dass eine chemische Reaktion zwischen zwei Verbindungen stattgefunden hat, bei Hitzeeinwirkung Gase freisetzt, wodurch das Volumen der Verbindung um ein Vielfaches des ursprünglichen Volumens zunimmt;
• bedeutet "dämmschichtbildend", dass im Brandfall ein fester mikroporöser Kohleschaum entsteht, so dass die gebildete feinporige und dicke Schaumschicht, die sogenannte Aschekruste, je nach Zusammensetzung ein Substrat gegen Hitze isoliert;
• ist ein "Kohlenstofflieferant" eine organische Verbindung, die durch unvollständige Verbrennung ein Kohlenstoffgerüst hinterlässt und nicht vollständig zu Kohlendioxid und Wasser verbrennt (Carbonifizierung); diese Verbindungen werden auch als "Kohlenstoffgerüstbildner" bezeichnet;
• ist ein "Säurebildner" eine Verbindung, die sich unter Hitzeeinwirkung, d.h. oberhalb etwa 150°C beispielsweise durch Zersetzung eine nicht flüchtige Säure bildet und dadurch als Katalysator für die Carbonifizierung wirkt; zudem kann sie zur Erniedrigung der Viskosität der Schmelze des Bindemittels beitragen; hiermit gleichbedeutend wird der Begriff "Dehydrierungskatalysator" verwendet;
• ist ein "Treibmittel" eine Verbindung, die sich bei erhöhter Temperatur unter Entwicklung inerter, d.h. nicht-brennbarer Gase zersetzt und das durch die Carbonifizierung gebildet Kohlenstoffgerüst und gegebenenfalls das Erweichte Bindemittel zu einem Schaum aufbläht (Intumeszenz); dieser Begriff wird gleichbedeutend mit "Gasbildner" verwendet;
• ist ein "Aschekrustenstabilisator" eine sogenannte gerüstbildende Verbindung, die das Kohlenstoffgerüst (Aschekruste), das aus dem Zusammenwirken der Kohlenstoffbildung aus der Kohlenstoffquelle und dem Gas aus dem Treibmittel, oder der physikalischen Intumeszenz gebildet wird, stabilisiert. Die prinzipielle Wirkungsweise ist dabei die, dass die an sich sehr weichen entstehenden Kohlenstoffschichten durch anorganische Verbindungen mechanisch verfestigt werden. Die Zugabe eines solchen Aschekrustenstabilisators trägt zu einer wesentlichen Stabilisierung der Intumeszenzkruste im Brandfall bei, da diese Additive die mechanische Festigkeit der intumeszierenden Schicht erhöhen und/oder deren Abtropfen verhindern, wodurch die isolierende Wirkung des Schaums aufrechterhalten oder verstärkt wird.
• ist ein "Oligomer" ein Molekül mit 2 bis 5 Wiederholungseinheiten und ist ein "Polymer" ein Molekül mit 6 oder mehr Wiederholungseinheiten und können Strukturen aufweisen, die linear, verzweigt, sternförmig, gewunden, hyperverzweigt oder vernetzt sind; Polymere können eine einzelne Art von Wiederholungseinheit aufweisen ("Homopolymere") oder sie können mehr als eine Art von Wiederholungseinheiten aufweisen ("Copolymere"). Wie hierin verwendet, ist "Harz" ein Synonym für Polymer.
• Bedeutet "Epoxidäquivalentmasse" diejenige Menge an Epoxidharz in [g], die ein Äquivalent [Val] Epoxidfunktionen besitzt und berechnet sich aus der Molmasse M in [g/Mol] dividiert durch die Funktionalität f in [Val/Mol]; (EEW [g/Val]);
• "ein", "eine", "einer" als Artikel vor einer chemischen Verbindungsklasse, dass eine oder mehrere unter diese chemische Verbindungsklasse fallende Verbindungen gemeint sein können. In einer bevorzugten Ausführungsform ist mit diesem Artikel nur eine einzelne Verbindung gemeint;
• "mindestens ein", "mindestens eine", "mindestens einer" zahlenmäßig "ein oder mehrere". In einer bevorzugten Ausführungsform ist mit diesem Begriff zahlenmäßig "ein", "eine", "einer" gemeint;
• "enthalten", "umfassen" und "beinhalten", dass neben den genannten Bestandteilen noch weitere vorhanden sein können. Diese Begriffe sind einschließlich gemeint und umfassen daher auch "bestehen aus". "Bestehen aus" ist abschließend gemeint und bedeutet, dass keine weiteren Bestandteile vorhanden sein können. In einer bevorzugten Ausführungsform bedeuten die Begriffe "enthalten", "umfassen" und "beinhalten" den Begriff "bestehen aus";
• "etwa" oder "circa" oder "ca." vor einem Zahlenwert einen Bereich von ± 5% dieses Wertes, bevorzugt ± 2% dieses Wertes, bevorzugter ± 1% dieses Wertes, besonders bevorzugt ± 0% dieses Wertes (also genau diesen Wert);
• ein durch Zahlen begrenzter Bereich, z.B. "von 80°C bis 120°C", dass die beiden Eckwerte und jeder Wert innerhalb dieses Bereichs einzeln offenbart sind.

For a better understanding of the invention, the following explanations of the terminology used herein are believed to be useful. According to the invention:

• " multifunctional " means that the compound in question has more than one functional group per molecule; accordingly, multifunctional in connection with epoxy compounds means that they have more than one epoxy group per molecule, and with regard to thiol-functionalized compounds, for example, that they have at least two thiol groups (-SH) per molecule and, with regard to amine-functionalized compounds, that they have at least two amine groups (-NR ₃ ) per molecule; the total number of the respective functional groups is the functionality of the corresponding compound;
• “ skeleton ” of the epoxy resin or the thiol-functionalized compound means the other part of the molecule to which the functional epoxy or thiol group can be attached;
• " Chemical intumescence " means the formation of a voluminous, insulating layer of ash by means of coordinated compounds which react with one another when exposed to heat;
• " Physical intumescence " means the formation of a voluminous, insulating layer by the expansion of a connection which, without a chemical reaction between two connections having taken place, releases gases when exposed to heat, whereby the volume of the connection increases many times its original volume;
• " Forming an insulating layer " means that in the event of a fire, a solid, microporous carbon foam is created, so that the fine-pored and thick foam layer formed, the so-called ash crust, depending on its composition, insulates a substrate against heat;
• a " carbon supplier " is an organic compound which, through incomplete combustion, leaves behind a carbon structure and does not burn completely to form carbon dioxide and water (carbonification); these compounds are also referred to as " carbon skeleton formers ";
• an " acid generator " is a compound that forms a non-volatile acid under the action of heat, ie above about 150 ° C., for example through decomposition, and thus acts as a catalyst for carbonification; in addition, it can contribute to lowering the viscosity of the melt of the binder; The term “ dehydrogenation catalyst ” is used synonymously with this;
• a " propellant " is a compound which decomposes at elevated temperature with the development of inert, ie non-flammable gases and which expands the carbon structure formed by the carbonification and optionally the softened binder to form a foam (intumescence); this term is used synonymously with " gas former ";
• an " ash crust stabilizer " is a so-called framework-forming compound that stabilizes the carbon framework (ash crust), which is formed from the interaction of carbon formation from the carbon source and the gas from the propellant, or physical intumescence. The principle mode of operation is that the carbon layers that are created, which are very soft, are mechanically strengthened by inorganic compounds become. The addition of such an ash crust stabilizer contributes to a significant stabilization of the intumescent crust in the event of fire, since these additives increase the mechanical strength of the intumescent layer and / or prevent it from dripping off, as a result of which the insulating effect of the foam is maintained or enhanced.
• an " oligomer " is a molecule with 2 to 5 repeating units and a " polymer " is a molecule with 6 or more repeating units and can have structures that are linear, branched, star-shaped, twisted, hyperbranched, or crosslinked; Polymers can have a single type of repeat unit ("homopolymers") or they can have more than one type of repeat unit ("copolymers"). As used herein, "resin" is synonymous with polymer.
• " Epoxy equivalent mass " means that amount of epoxy resin in [g] which has one equivalent [Val] epoxy functions and is calculated from the molar mass M in [g / mol] divided by the functionality f in [Val / mol]; (EEW [g / Val]);
• “a”, “an”, “an” as an article in front of a chemical compound class means that one or more compounds falling under this chemical compound class can be meant. In a preferred embodiment, this article means only a single compound;
• "at least one", "at least one", "at least one" numerically "one or more". In a preferred embodiment, this term means numerically “a”, “an”, “an” ;
• “contain”, “comprise” and “contain” mean that further components may be present in addition to the constituents mentioned. These terms are intended to be inclusive and therefore also include “consist of”. “Consists of” is meant conclusively and means that no further constituents can be present. In a preferred embodiment, the terms “contain”, “comprise” and “include” mean the term “consist of” ;
• "about" or "circa" or "approx." in front of a numerical value, a range of ± 5% of this value, preferably ± 2% of this value, more preferably ± 1% of this value, particularly preferably ± 0% of this value (i.e. precisely this value);
• a range limited by numbers, eg " from 80 ° C. to 120 ° C.", that the two benchmarks and each value within this range are disclosed individually.

In general, it is believed that reacting an epoxy resin having a functionality of two with a thiol-functionalized or amine-functionalized compound having a functionality of two will result in linear molecular structures. Often it is necessary to produce molecular structures that are branched and / or crosslinked, which probably requires the use of at least one ingredient with a functionality greater than two. The epoxy resin and / or the thiol- or amine-functionalized compound is therefore preferably multifunctional, the multifunctional epoxy resin or the multifunctional amine- or thiol-functionalized compound or both more preferably having a functionality greater than two (> 2).

1. a) Reaktionsprodukte von Epichlorhydrin mit Bisphenol A;
2. b) Reaktionsprodukte von Epichlorhydrin mit Bisphenol S
3. c) Epoxy-Novolake auf Phenol- oder Cresolbasis;
4. d) Aromatische Glycidylaminharze;
5. e) Epoxidharze ohne aromatische Struktureinheiten;

sowie Gemische zweier oder mehrerer derartiger Epoxidharze in beliebigem Verhältnis und in beliebigen Reinheitsgraden.Epoxy resins customary in epoxy chemistry are suitable as the epoxy resin. These are obtained in a known manner, for example from the oxidation of the corresponding olefins or from the reaction of epichlorohydrin with the corresponding polyols, polyphenols or amines. Basic information on and examples of epoxy resins can be found in the chapter " Epoxy Resins "from the Encyclopedia of Polymer Sciences and Technology, Vol. 9, Wiley-Interscience, 2004 , refer to. Examples of suitable epoxy resins are reaction products of polyhydroxy compounds, in particular polyhydric phenols or phenol-aldehyde condensates, with epihalohydrins or their precursors, in particular:

1. a) reaction products of epichlorohydrin with bisphenol A;
2. b) Reaction products of epichlorohydrin with bisphenol S.
3. c) epoxy novolaks based on phenol or cresol;
4. d) aromatic glycidylamine resins;
5. e) epoxy resins without aromatic structural units;

and mixtures of two or more such epoxy resins in any ratio and in any degree of purity.

• Dihydroxybenzol-Derivaten wie Resorcin, Hydrochinon und Brenzkatechin;
• weiteren Bisphenolen oder Polyphenolen wie Bis-(4-hydroxy-3-methylphenyl)-methan, 2,2-Bis-(4-hydroxy-3-methylyphenyl)-propan (Bisphenol-C), Bis-(3,5-dimethyl-4-hydroxyphenyl)-methan, 2,2-Bis-(3,5-dimethyl-4-hydroxyphenyl)-propan, 2,2-Bis-(3,5-dibromo-4-hydroxyphenyl)-propan, 2,2-Bis-(4-hydroxy-3-tert.-butylphenyl)-propan, 2,2-Bis-(4-hydroxyphenyl)-butan (Bisphenol-B), 3,3-Bis-(4-hydroxyphenyl)-pentan, 3,4-Bis-(4-hydroxyphenyl)-hexan, 4,4-Bis-(4-hydroxyphenyl)-heptan, 2,4-Bis-(4-hydroxyphenyl)-2-methylbutan, 2,4-Bis-(3,5-dimethyl-4-hydroxyphenyl)-2-methylbutan, 1,1-Bis-(4-hydroxyphenyl)-cyclohexan (Bisphenol-Z), 1,1-Bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexan (Bisphenol-TMC), 1,1-Bis-(4-hydroxyphenyl)-1-phenyl-ethan, 1,4-Bis[2-(4-hydroxyphenyl)-2-propyl]-benzol) (Bisphenol-P), 1,3-Bis-[2-(4-hydroxyphenyl)-2-propyl]-benzol) (Bisphenol-M), 4,4'-Dihydroxydiphenyl (DOD), 4,4'-Dihydroxybenzophenon, Bis-(2-hydroxynaphth-1-yl)-methan, Bis-(4-hydroxynaphth-1-yl)-methan 1,5-Dihydroxynaphthalin, Tris-(4-hydroxyphenyl)-methan, 1,1,2,2-Tetrakis-(4-hydroxyphenyl)-ethan Bis-(4-hydroxyphenyl)-ether, Bis-(4-hydroxyphenyl)sulfon;
• Kondensationsprodukten von Phenolen mit Formaldehyd, die unter sauren Bedingungen erhalten werden, wie Phenol-Novolaken oder Kresol-Novolaken, auch Bisphenol-F-Novolake genannt;
• aromatischen Aminen, wie Anilin, Toluidin, 4-Aminophenol, 4,4'-Methylendiphenyldiamin (MDA), 4,4'-Methylendiphenyldi-(N-methyl)-amin, 4,4'-[1,4-Phenylen-bis-(1-methyl-ethyliden)]-bisanilin (Bisanilin-P), 4,4'-[1,3-Phenylen-bis-(1-methyl-ethyliden)]-bisanilin (Bisanilin-M);
• sowie Gemische zweier oder mehrerer derartiger Epoxidharze in beliebigem Verhältnis und in beliebigen Reinheitsgraden.

Particularly suitable as epoxy resin are so-called polyepoxy liquid resins, hereinafter referred to as “liquid resin”. These have a glass transition temperature which is usually below 25 ° C, in contrast to the so-called solid resins, which have a glass transition temperature above 25 ° C and can be comminuted to give powders which can be poured at 25 ° C. Suitable compounds are the glycidylation products of:

• Dihydroxybenzene derivatives such as resorcinol, hydroquinone and catechol;
• other bisphenols or polyphenols such as bis (4-hydroxy-3-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylyphenyl) propane (bisphenol-C), bis (3,5-dimethyl) -4-hydroxyphenyl) methane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2, 2-bis- (4-hydroxy-3-tert.-butylphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane (bisphenol-B), 3,3-bis (4-hydroxyphenyl) - pentane, 3,4-bis- (4-hydroxyphenyl) -hexane, 4,4-bis- (4-hydroxyphenyl) -heptane, 2,4-bis- (4-hydroxyphenyl) -2-methylbutane, 2,4- Bis- (3,5-dimethyl-4-hydroxyphenyl) -2-methylbutane, 1,1-bis- (4-hydroxyphenyl) -cyclohexane (bisphenol-Z), 1,1-bis- (4-hydroxyphenyl) -3 , 3,5-trimethylcyclohexane (bisphenol-TMC), 1,1-bis- (4-hydroxyphenyl) -1-phenyl-ethane, 1,4-bis [2- (4-hydroxyphenyl) -2-propyl] -benzene ) (Bisphenol-P), 1,3-bis- [2- (4-hydroxyphenyl) -2-propyl] -benzene) (bisphenol-M), 4,4'-dihydroxydiphenyl (DOD), 4,4'- Dihydroxybenzophenone, bis (2-hydroxynaphth-1-yl) methane, bis (4-hydroxynaphth-1-yl) methane 1,5-dihydroxynaphthal in, tris (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfone;
• Condensation products of phenols with formaldehyde, which are obtained under acidic conditions, such as phenol novolaks or cresol novolaks, also called bisphenol-F novolaks;
• aromatic amines such as aniline, toluidine, 4-aminophenol, 4,4'-methylenediphenyldiamine (MDA), 4,4'-methylenediphenyldi- (N-methyl) amine, 4,4 '- [1,4-phenylene-bis - (1-methyl-ethylidene)] bisaniline (bisaniline-P), 4,4 '- [1,3-phenylene-bis- (1-methyl-ethylidene)] bisaniline (bisaniline-M);
• and mixtures of two or more such epoxy resins in any ratio and in any degree of purity.

Further preferred in the context of the invention are reaction products of epichlorohydrin with bisphenol A with an epoxide equivalent weight (EEW) 550 g / eq; Reaction products of epichlorohydrin with bisphenol F, the simplest representative of the novolaks, with an EEW ≤ 500 g / eq; any mixtures of these two reaction products, reaction products of any mixture of bisphenol A and bisphenol F with epichlorohydrin, epoxy resins such as hydantoin-based epoxy resins or diglycidyl ethers of hydrogenated bisphenol A or bisphenol F; and mixtures of two or more such epoxy resins in any ratio and in any degree of purity.

Reaction products of epichlorohydrin with bisphenol A with an EEW 330 g / eq; Reaction products of epichlorohydrin with bisphenol F, the simplest representative of novolaks, with an EEW ≤ 300 g / val, any mixture of these two reaction products, reaction products of any mixture of bisphenol A and bisphenol F with epichlorohydrin with an EEW ≤ 330 g / val, 5 , 5-dimethyl-1,3-bis (2,3-epoxypropyl) -2,4-imidazolidinedione; 2,2-bis [4- (2,3-epoxypropoxy) cyclohexyl] propane; and mixtures of two or more such epoxy resins in any ratio and in any degree of purity.

Reaction products of epichlorohydrin with bisphenol A with an EEW 200 g / eq, such as Epilox® A 17-01, Epilox® A 18-00, Epilox® A 19-00, Epilox® A 19-02, Epilox, are very particularly preferred ® A 19-03 or Epilox® A 19-04 from Leuna-Harze GmbH, represented by the following formula, where 0 n 0.2;

sowie Gemische zweier oder mehrerer derartiger Epoxidharze in beliebigem Verhältnis und in beliebigen Reinheitsgraden, wie beispielsweise Epilox® AF 18-30, Epilox® 18-50 oder Epilox® T 19-27 der Leuna-Harze GmbH, sowie Reaktionsprodukte eines beliebigen Gemisches von Bisphenol A und Bisphenol F mit Epichlorhydrin mit einem EEW ≤ 200 g/Val.Reaction products of epichlorohydrin with bisphenol F, the simplest representative of novolaks, with an EEW ≤ 185 g / eq, such as Epilox® F 16-01 or Epilox® F 17-00 from Leuna-Harze GmbH, represented by the following formula, wherein 0 ≤ n 0.2;

and mixtures of two or more such epoxy resins in any ratio and in any degree of purity, such as Epilox® AF 18-30, Epilox® 18-50 or Epilox® T 19-27 from Leuna-Harze GmbH, as well as reaction products of any mixture of bisphenol A. and bisphenol F with epichlorohydrin with an EEW ≤ 200 g / eq.

• ein Glycidylether eines gesättigten oder ungesättigten, verzweigten oder unverzweigten, zyklischen oder offenkettigen C₂- bis C₃₀-Diols, wie beispielsweise Ethylenglykol, Propylenglykol, Butylenglykol, Hexandiol, Octandiol, ein Polypropylenglykol, Dimethylolcyclohexan, Neopentylglykol oder Dibromoneopentylglykol;
• ein Glycidylether eines tri- oder tetrafunktionellen, gesättigten oder ungesättigten, verzweigten oder unverzweigten, zyklischen oder offenkettigen Polyols wie Rizinusöl, Trimethylolpropan, Trimethylolethan, Pentaerythritol, Sorbit oder Glycerin, sowie alkoxyliertes Glycerin oder alkoxyliertes Trimethylolpropan;
• ein hydriertes Bisphenol-A-, -F- oder -A/F-Flüssigharz, beziehungsweise die Glycidylisierungsprodukte von hydriertem Bisphenol-A, -F oder-A/F;
• ein N-Glycidylderivat von Amiden oder heterocyclischen Stickstoffbasen, wie Triglycidylcyanurat und Triglycidylisocyanurat, sowie Umsetzungsprodukte von Epichlorhydrin und Hydantoin.

An aliphatic or cycloaliphatic polyepoxide is also suitable as the epoxy resin, such as:

• a glycidyl ether of a saturated or unsaturated, branched or unbranched, cyclic or open-chain C ₂ to C ₃₀ diol, such as, for example, ethylene glycol, propylene glycol, butylene glycol, hexanediol, octanediol, a polypropylene glycol, dimethylolcyclohexane, neopentylglyomoneoplycol or dibromone glycol;
• a glycidyl ether of a tri- or tetrafunctional, saturated or unsaturated, branched or unbranched, cyclic or open-chain polyol such as castor oil, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol or glycerol, as well as alkoxylated glycerol or alkoxylated trimethylolpropane;
• a hydrogenated bisphenol-A, -F or -A / F liquid resin, or the glycidylation products of hydrogenated bisphenol-A, -F or-A / F;
• an N-glycidyl derivative of amides or heterocyclic nitrogen bases, such as triglycidyl cyanurate and triglycidyl isocyanurate, and reaction products of epichlorohydrin and hydantoin.

A bisphenol A, F or A / F solid resin, which has a similar structure to the liquid resins of the above two formulas, but instead of the index n has a value of 2 to 12 and a glass transition temperature above, are also possible as epoxy resin of 25 ° C.

Finally, epoxy resins from the oxidation of olefins, for example from the oxidation of vinylcylohexene, dicyclopentadiene, cyclohexadiene, cyclododecadiene, cyclododecatriene, isoprene, 1,5-hexadiene, butadiene, polybutadiene or divinylbenzene are also suitable as epoxy resin.

Depending on the functionality of the epoxy resin, the degree of crosslinking of the binder and thus, on the one hand, the strength of the resulting coating and its elastic properties can be adjusted. At the same time, this has a direct influence on the achievable expansion of the resulting ash crust in the event of fire.

By adding at least one reactive diluent, the viscosity of the composition can be set or adapted according to the application properties.

In one embodiment of the invention, the composition therefore contains further compounds containing epoxy groups as reactive diluents, if necessary. These compounds contain one or more epoxy groups. In principle, any low-viscosity compound that carries at least one epoxy group per molecule can be used. Two or more different reactive diluents can be combined. Suitable examples are allyl glycidyl ether, butyl glycidyl ether (BGE), 2-ethylhexyl glycidyl ether, alkyl glycidyl ether (C ₁₂ -C ₁₄ ), tridecyl glycidyl ether, phenyl glycidyl ether (PGE), o -resol glycidyl ether (GE), rd glycidyl ether (CGE), p - tertiary glycidyl ether (CGE), p - tertiary butyl ether 4-butanediol diglycidyl ether (BDGE), 1,6-hexanediol diglycidyl ether (HDGE), cyclohexanedimethanol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, epoxidized vegetable oil glycidyl ether, and epoxidized, oxidized vegetable oil glycidyl ether, such as epoxidized, oxidized vegetable oil glycidyl ether, such as epoxidized oxidized vegetable oil glycidyl ether, for example, polypropyleneglycol diglycidyl ether, e.g.

In one embodiment of the invention, the intumescent composition comprises a curing agent for the epoxy resin.

Any amine- or thiol-functionalized compound which can react with epoxy compounds can expediently be used as curing agent.

Any compound which has at least two thiol groups can expediently be used as the thiol-functionalized compound. Each thiol group is attached to a framework either directly or via a linker.

The thiol functionalized compound of the present invention can have any of a wide variety of backbones, and these can be the same or different.

According to the invention, the structure is a monomer, an oligomer or a polymer.

In some embodiments of the present invention, the frameworks comprise monomers, oligomers or polymers with a molecular weight (Mw) of 50,000 g / mol or less, preferably 25,000 g / mol or less, more preferably 10,000 g / mol or less, even more preferably 5,000 g / mol or less, even more preferably 2,000 g / mol or less, and most preferably 1,000 g / mol or less.

As monomers useful as skeletons, there can be mentioned, for example, alkanediols, alkylene glycols, sugars, polyvalent derivatives thereof or mixtures thereof, and amines such as ethylenediamine and hexamethylenediamine, and thiols. The following can be mentioned by way of example as oligomers or polymers which are suitable as frameworks: polyalkylene oxide, polyurethane, polyethylene vinyl acetate, polyvinyl alcohol, polydiene, hydrogenated polydiene, alkyd, alkyd polyester, (meth) acrylic polymer, polyolefin, polyester, halogenated polyolefin, halogenated polyester, polymercaptan , as well as copolymers or mixtures thereof.

In preferred embodiments of the invention, the skeleton is a polyhydric alcohol or a polyhydric amine, it being possible for these to be monomeric, oligomeric or polymeric. More preferably the backbone is a polyhydric alcohol.

The following can be mentioned as examples of polyhydric alcohols which are suitable as frameworks: alkanediols such as butanediol, pentanediol, hexanediol, alkylene glycols such as ethylene glycol, propylene glycol and polypropylene glycol, glycerol, 2- (hydroxymethyl) propane-1,3-diol, 1,1,1-tris (hydroxymethyl) ethane, 1,1,1-trimethylolpropane, di (trimethylolpropane), tricyclodecanedimethylol, 2,2,4-trimethyl-1,3-pentanediol, bisphenol A, cyclohexanedimethanol, alkoxylated and / or ethoxylated and / or propoxylated derivatives of neopentyl glycol, tertraethylene glycol cyclohexanedimethanol, hexanediol, 2- (hydroxymethyl) propane-1,3-diol, 1,1,1-tris (hydroxymethyl) ethane, 1,1,1-trimethylolpropane and castor oil, pentaerythritol, Sugar, polyvalent derivatives thereof or mixtures thereof.

1. 1: Bindung zur funktionellen Gruppe
2. 2: Bindung zum Gerüst

Any units which are suitable for connecting the skeleton and functional group can be used as linkers. For thiol-functionalized compounds, the linker is preferably selected from structures (I) to (XI).

1. 1: Bond to the functional group
2. 2: Bond to the framework

Structures (I), (II), (III) and (IV) are particularly preferred as linkers for thiol-functionalized compounds.

Particularly preferred thiol-functionalized compounds are esters of α-thioacetic acid (2-mercaptoacetate), β-thiopropionic acid (3-mercaptopropionate) and 3-thiobutyric acid (3-mercaptobutyrate) with monoalcohols, diols, triols, tetraols, pentaols or other polyols and 2 -Hydroxy-3-mercaptopropyl derivatives of monoalcohols, diols, triols, tetraols, pentaols or other polyols. Mixtures of alcohols can also be used as the basis for the thiol-functionalized compound be used. In this regard, reference is made to the WO 99/51663 A1 , the content of which is hereby incorporated into this application.

Examples of particularly suitable thiol-functionalized compounds are: glycol bis (2-mercaptoacetate), glycol bis (3-mercaptopropionate), 1,2-propylene glycol bis (2-mercaptoacetate), 1,2-propylene glycol bis (3-mercaptopropionate), 1,3-propylene glycol bis (2-mercaptoacetate), 1,3-propylene glycol bis (3-mercaptopropionate), tris (hydroxymethyl) methane-tris (2-mercaptoacetate), tris (hydroxymethyl) methane -tris (3-mercaptopropionate), 1,1,1-tris (hydroxymethyl) ethane-tris (2-mercaptoacetate), 1,1,1-tris (hydroxymethyl) ethane-tris (3-mercaptopropionate), 1,1, 1-trimethylolpropane-tris (2-mercaptoacetate), ethoxylated 1,1,1-trimethylolpropane-tris (2-mercaptoacetate), propoxylated 1,1,1-trimethylolpropane-tris (2-mercaptoacetate), 1,1,1-trimethylolpropane -tris (3-mercaptopropionate), ethoxylated 1,1,1-trimethylolpropane-tris (3-mercaptopropionate), propoxylated trimethylolpropane-tris (3-mercaptopropionate), 1,1,1-trimethylolpropane-tris (3-mercaptobutyrate), pentaerythritol -tris (2-mercaptoacetate), pentaerythr itol-tetrakis (2-mercaptoacetate), pentaerythritol-tris (3-mercaptopropionate), pentaerythritol-tetrakis (3-mercaptopropionate), pentaerythritol-tris (3-mercaptobutyrate), pentaerythritol 3--tetrakis (3-mercaptobutyrate) (3-mercaptobutyrate) BASF), GPM-800 (Gabriel Performance Products), Capcure LOF (BASF), GPM-800LO (Gabriel Performance Products), KarenzMT PE-1 (Showa Denko), 2-ethylhexyl thioglycolate, iso- octyl thioglycolate, di ( n- butyl) thiodiglycolate, glycol di-3-mercaptopropionate, 1,6-hexanedithiol, ethylene glycol bis (2-mercaptoacetate) and tetra (ethylene glycol) dithiol.

The thiol-functionalized compound can be used alone or as a mixture of two or more different thiol-functionalized compounds.

Depending on the functionality of the thiol-functionalized compound, the degree of crosslinking of the binder and thus, on the one hand, the strength of the resulting coating and its elastic properties can be adjusted. At the same time, this has a direct influence on the achievable expansion of the resulting ash crust in the event of fire.

In the composition of the present invention, the relative proportion of epoxy resins to thiol-functionalized compounds can be determined by the reactive equivalent ratio, which is the ratio of the number of all epoxy groups in the Composition is to be characterized by the number of thiol groups in the composition. The reactive equivalent ratio is 0.1 to 10: 1, preferably 0.2 to 5: 1, more preferably 0.3 to 3: 1, even more preferably 0.5 to 2: 1 and even more preferably 0.75 to 1 , 25: 1.

As an alternative or additional hardener component, which is also referred to as a co-hardener, an amine hardener that is customary for epoxy resins can be used.

In particular, aliphatic or aromatic amines, amidoamines, polyamides, polyamine-epoxy resin adducts and / or ketimines have proven useful. The amine hardeners can be used individually or as a mixture of two or more compounds. Examples are ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine (DETA), tetraethylenetetramine (TETA), isophoronediamine (IPDA), m -xylylenediamine (mXDA), N-methylbenzylamine (NMB) or the Ancamide® (Air Products), diethylaminopropylamine (DEAPA) N- aminoethylpiperazine (N-AEP), diaminodiphenyl sulfone (DDS), 1,8-diamino-p-menthane (MDA). Likewise, polyetheramines such as Jeffamine® D-230 (Huntsman), Jeffamine® D-400 (Huntsman), Jeffamine® T-403 (Huntsman) can be used.

The coating properties can be adjusted via a suitably selected mixture of thiol-functionalized compound and amine-functionalized compound as hardener for the epoxy resin.

In a preferred embodiment of the invention the curing agent is a thiol-functionalized compound.

In a further embodiment of the invention, the curing agent is a combination of a thiol-functionalized compound and an amine-functionalized compound.

If the curing, ie the reaction of the epoxy resin with the amine-functionalized or the thiol-functionalized compound, takes place too slowly, a catalyst can be used for the curing. The use of a catalyst can ensure that the compositions quickly, ie within a few minutes, and cure completely even at room temperature. This makes such compositions very attractive for use in the field, such as on the construction site.

The compounds usually used for reactions between epoxy resins and amine-functionalized or thiol-functionalized compounds, such as tertiary amines, for example benzyldimethylamine, N, N-dimethylpropylamine, 1,8-diazabicyclo [5.4.0] undec-7-en and Bis-N, N-dimethylethanolamine ethers, phenol derivatives, eg nonylphenol, and the like, which are known to those skilled in the art, can be used. In this regard, reference is made to the WO 2012/08224 A1 , the content of which is hereby incorporated into this application.

in der R¹ Wasserstoff oder ein linearer oder verzweigter C₁-C₁₅-Alkylrest ist, R² (CH₂)_nNR⁵R⁶- oder NH(CH₂)_nNR⁵R⁶- ist, in denen R⁵ und R⁶ unabhängig voneinander ein linearer oder verzweigter C₁-C₁₅-Alkylrest sind und n = 0 oder 1 ist, R³ und R⁴ unabhängig voneinander Wasserstoff, (CH₂)_nNR⁷R⁸ oder NH(CH₂)_nNR⁷R⁸ sind, R⁷ und R⁸ unabhängig voneinander Wasserstoff oder ein linearer oder verzweigter C₁-C₁₅-Alkylrest sind und n = 0 oder 1 ist.In a preferred embodiment of the invention, constituent B also contains an aminophenol or an ether thereof, which has at least one tertiary amino group, optionally together with a primary and / or secondary amino group, as a catalyst. The catalyst is preferably selected from compounds of the general formula (XX),

in which R ^{1 is} hydrogen or a linear or branched C ₁ -C ₁₅ -alkyl radical, R ² (CH ₂ ) _n NR ⁵ R ⁶ - or NH (CH ₂ ) _n NR ⁵ R ⁶ -, in which R ⁵ and R ⁶ independently of one another are a linear or branched C ₁ -C ₁₅ -alkyl radical and n = 0 or 1, R ³ and R ⁴ independently of one another are hydrogen, (CH ₂ ) _n NR ⁷ R ⁸ or NH (CH ₂ ) _n NR ⁷ R ⁸ are, R ⁷ and R ^{8 are} independently hydrogen or a linear or branched C ₁ -C ₁₅ -alkyl radical and n = 0 or 1.

R ¹ is preferably hydrogen or a C ₁ -C ₁₅ -alkyl radical, in particular a linear C ₁ -C ₁₅ -alkyl radical, more preferably methyl or ethyl and most preferably methyl.

The phenol of the formula (XX) is preferably substituted in the 2-, 4- and 6-position, ie the substituents R ² , R ³ and R ⁴ are in the 2-, 4- and 6-position.

In the event that R ⁵ , R ⁶ , R ⁷ and R ^{8 are} alkyl radicals, these are preferably a C ₁ -C ₅ -alkyl radical, more preferably methyl or ethyl and most preferably methyl.

Either a compound or a mixture of at least two compounds of the formula (XX) can be used as the catalyst.

The catalyst is preferably selected from 2,4,6-tris (dimethylaminomethyl) phenol, bis (dimethylaminomethyl) phenol and 2,4,6-tris (dimethylamino) phenol. Most preferably the catalyst is 2,4,6-tris (dimethylaminomethyl) phenol.

A preferred catalyst mixture contains 2,4,6-tris (dimethylaminomethyl) phenol and bis (dimethylaminomethyl) phenol. Such mixtures are e.g. commercially available as Ancamine® K-54 (AirProducts, Belgium).

In order for the composition to be able to protect the component to which it was applied from fire or against the effects of great heat, for example as a result of a fire, it is necessary that the composition forms an insulating layer as a result of the temperature input.

For this purpose, compounds, also known as intumescent additives, are used which, through the formation of an inflated, insulating layer of flame-retardant material that forms under the action of heat, protects the substrate from overheating and thus prevents the mechanical and static properties of structural components from changing due to the action of heat or at least delayed. The formation of a voluminous, insulating layer, namely a layer of ash, can be formed by the chemical reaction of a mixture of correspondingly coordinated compounds that react with one another when exposed to heat. Such systems are known to the person skilled in the art by the term chemical intumescence and can be used according to the invention. Alternatively, the bulky, insulating layer can be created by puffing up a single compound, without involving any chemical Reaction between two compounds has taken place, gases are formed when exposed to heat. Such systems are known to the person skilled in the art by the term physical intumescence and can also be used according to the invention. Both systems can be used according to the invention either alone or together as a combination.

For the formation of an intumescent layer by chemical intumescence, at least three components are generally required, a carbon supplier, a dehydrogenation catalyst (also called acid generator) and a blowing agent, which are contained in a binder in coatings, for example. When exposed to heat, the binding agent softens and the fire protection additives are released, so that in the case of chemical intumescence they can react with one another or in the case of physical intumescence they can expand. Through thermal decomposition, the acid is formed from the dehydrogenation catalyst, which serves as a catalyst for the carbonification of the carbon supplier. At the same time, the propellant decomposes thermally with the formation of inert gases, which cause the carbonized (charred) material and, if necessary, the softened binder to expand, with the formation of a voluminous, insulating foam.

It should be mentioned that, in the event of a fire, the binder itself can also have the function of a carbon supplier and / or propellant. The composition according to the invention comprises an epoxy resin which, due to its functional groups and its carbon structure, can fulfill both the function of a carbon supplier and that of a propellant. This means that additional carbon suppliers and propellants can be dispensed with. According to the invention, the composition therefore contains an acid generator.

Suitable acid generators or dehydrogenation catalysts are the compounds commonly used in intumescent fire protection formulations and known to the person skilled in the art, in particular a salt or an ester of an inorganic, non-volatile acid selected from sulfuric acid, phosphoric acid or boric acid. Essentially, phosphorus-containing compounds are used, the range of which is very large, as they extend over several oxidation levels of phosphorus, such as phosphines, Phosphine oxides, phosphonium compounds, phosphates, elemental red phosphorus, phosphites and phosphates. As phosphoric acid compounds, there may be mentioned by way of example: monoammonium phosphate, diammonium phosphate, ammonium phosphate, ammonium polyphosphate, melamine phosphate, melamine resin phosphates, potassium phosphate, polyol phosphates such as pentaerythritol phosphate, glycerol phosphate, sorbitol phosphate and the like, diphrate phosphate phosphate, phosphate phosphate tenta phosphate, phosphate phosphate, diphrate phosphate, diphrate phosphate tenta, phosphate phosphate, diphrate phosphate tenta phosphate, phosphate phosphate, phosphate phosphate, phosphate phosphate, diphrate phosphate tenta A polyphosphate or an ammonium polyphosphate is preferably used as the phosphoric acid compound. Melamine resin phosphates are to be understood as meaning compounds such as reaction products of Lamelite C (melamine-formaldehyde resin) with phosphoric acid. As sulfuric acid compounds, there can be exemplified: ammonium sulfate, ammonium sulfamate, nitroaniline bisulfate, 4-nitroaniline-2-sulfonic acid and 4,4-dinitrosulfanilamide and the like. As the boric acid compound, melamine borate can be exemplified.

In one embodiment of the invention, the composition can contain a carbon supplier as an additional intumescent additive.

The compounds commonly used in intumescent fire protection formulations and known to the person skilled in the art can be considered as carbon suppliers, such as starch-like compounds, e.g. Starch and modified starch, and / or polyhydric alcohols (polyols), such as saccharides and polysaccharides and / or a thermoplastic or thermosetting polymeric resin binder, such as a phenolic resin, a urea resin, a polyurethane, polyvinyl chloride, poly (meth) acrylate, polyvinyl acetate, polyvinyl alcohol, a silicone resin and / or a rubber. Suitable polyols are polyols from the group consisting of sugar, pentaerythritol, dipentaerythritol, tripentaerythritol, polyvinyl acetate, polyvinyl alcohol, sorbitol, polyoxyethylene / polyoxypropylene (EO-PO) polyols. Pentaerythritol, dipentaerythritol or polyvinyl acetate are preferably used.

In a further embodiment of the invention, the composition can contain a blowing agent as an additional intumescent additive.

Suitable blowing agents are the compounds customarily used in fire protection formulations and known to the person skilled in the art, such as cyanuric acid or isocyanic acid and its derivatives, melamine and its derivatives. Such are cyanamide, dicyanamide, dicyandiamide, guanidine and its salts, biguanide, melamine cyanurate, cyanic acid salts, cyanic acid esters and amides, hexamethoxymethylmelamine, dimelamine pyrophosphate, melamine polyphosphate, melamine phosphate. Hexamethoxymethylmelamine or melamine (cyanuric acid amide) is preferably used.

Components that do not restrict their mode of action to a single function are also suitable, such as melamine polyphosphate, which acts both as an acid generator and as a blowing agent. More examples are in the GB 2 007 689 A1 , EP 139 401 A1 and US-3,969,291 A1 described.

In a further embodiment of the invention, the composition can furthermore contain a thermally expandable compound, such as a graphite intercalation compound, which is also known as expandable graphite. These can also be incorporated into the binder.

Known intercalation compounds of SO _x , NO _x , halogen and / or strong acids in graphite can be used as expandable graphite. These are also known as graphite salts. Expandable graphites which release SO ₂ , SO ₃ , NO and / or NO ₂ at temperatures of, for example, 120 to 350 ° C. with expansion, are preferred. The expandable graphite can, for example, be in the form of platelets with a maximum diameter in the range from 0.1 to 5 mm. This diameter is preferably in the range from 0.5 to 3 mm. Expandable graphites suitable for the present invention are commercially available. In general, the expandable graphite particles are evenly distributed in the fire protection elements according to the invention. The concentration of expandable graphite particles can, however, also be varied in a point, pattern, area and / or sandwich fashion. In this regard, reference is made to the EP 1489136 A1 , the content of which is hereby incorporated into this application.

Since the ash crust formed in the event of fire is usually too unstable and, depending on its density and structure, can be blown by air currents, which has a negative effect on the insulating effect of the coating, at least one ash crust stabilizer is preferably added to the components listed above.

As ash crust stabilizers or framework formers, the compounds usually used in fire protection formulations and known to the person skilled in the art come into consideration, for example expandable graphite and particulate metals such as aluminum, magnesium, iron and zinc. The particulate metal can be in the form of a powder, flakes, flakes, fibers, filaments and / or whiskers, the particulate metal in the form of powder, flakes or flakes having a particle size of ≤ 50 μm, preferably from 0.5 to 10 μm owns. In the case of using the particulate metal in the form of fibers, filaments and / or whiskers, a thickness of 0.5 to 10 µm and a length of 10 to 50 µm are preferred. As an ash crust stabilizer, an oxide or a compound of a metal from the group comprising aluminum, magnesium, iron or zinc can be used, in particular iron oxide, preferably iron trioxide, titanium dioxide, a borate such as zinc borate and / or a glass frit made from low-melting glasses a melting temperature of preferably at or above 400 ° C., phosphate or sulfate glasses, melamine polyzinc sulfates, ferro glasses or calcium borosilicates. The addition of such an ash crust stabilizer contributes to a substantial stabilization of the ash crust in the event of fire, since these additives increase the mechanical strength of the intumescent layer and / or prevent it from dripping off. Examples of such additives can also be found in U.S. 4,442,157 A , U.S. 3,562,197 A , GB 755 551 A such as EP 138 546 A1 .

Ash crust stabilizers such as melamine phosphate or melamine borate can also be included.

One or more reactive flame retardants can optionally be added to the composition according to the invention. Such compounds are incorporated into the binder. An example within the meaning of the invention are reactive organophosphorus compounds such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and its derivatives, such as, for example, DOPO-HQ, DOPO-NQ, and adducts. Such compounds are described, for example, in S. V Levchik, E. D Weil, Polym. Int. 2004, 53 , 1901-1929.

In addition to the additives forming the insulating layer, the composition can optionally contain customary auxiliaries such as solvents such as xylene or toluene, wetting agents such as polyacrylates and / or polyphosphates, defoamers such as silicone defoamers, thickeners such as alginate thickeners, dyes, fungicides, plasticizers such as chlorine-containing waxes , Binders, flame retardants or various fillers such as vermiculite, inorganic fibers, quartz sand, glass microspheres, mica, silicon dioxide, mineral wool, and the like.

Additional additives such as thickeners, rheology additives and fillers can be added to the composition. The rheology additives such as anti-settling agents, anti-sagging agents and thixotropic agents are preferably polyhydroxycarboxamides, urea derivatives, salts of unsaturated carboxylic acid esters, alkylammonium salts of acidic phosphoric acid derivatives, ketoximes, amine salts of p-toluenesulfonic acid, or organic amine salts or mixtures of sulfonic acid derivatives. In addition, rheological additives based on pyrogenic or precipitated silicas or based on silanized pyrogenic or precipitated silicas can be used. The rheology additive is preferably pyrogenic silicas, modified and unmodified phyllosilicates, precipitated silicas, cellulose ethers, polysaccharides, PU and acrylate thickeners, urea derivatives, castor oil derivatives, polyamides and fatty acid amides and polyolefins, provided they are in powdered and / or solid form Suspending agents such as Xanthan gum.

The composition according to the invention can be made up as a two- or multi-component system.

The epoxy resin is preferably contained in the composition in an amount of 3 to 95% by weight, particularly preferably in an amount of 5 to 80% by weight.

If a reactive diluent is used, it is preferably contained in the composition in an amount of 0.25 to 70% by weight, particularly preferably in an amount of 0.5 to 50% by weight.

The amine-functionalized or the thiol-functionalized compound is preferably contained in the composition in an amount of 5 to 97% by weight, particularly preferably in an amount of 5 to 95% by weight. If a mixture of the amine-functionalized and the thiol-functionalized compound is used, the amounts just mentioned relate to the mixture.

The insulating layer-forming additives can be contained in the composition in an amount of 30 to 99% by weight, the amount essentially depending on the form of application of the composition (spraying, brushing and the like). In order to achieve the highest possible intumescence rate, the proportion in the composition is set as high as possible. The proportion in the composition is preferably 35 to 85% by weight and particularly preferably 40 to 85% by weight.

The composition can be applied to the substrate, in particular a metallic substrate, as a paste with a brush, a roller or by spraying. The composition is preferably applied by means of an airless spray process.

Compared with the solvent-based and water-based systems, the composition according to the invention is distinguished by high mechanical resistance.

The composition according to the invention is particularly suitable as a coating, in particular as a fire protection coating, preferably a sprayable coating, for substrates on a metallic and non-metallic basis. The substrates are not restricted and include components, in particular steel components and wooden components, but also individual cables, cable bundles, cable trays and cable ducts or other lines.

The composition according to the invention is used primarily in the construction sector as a coating, in particular a fire protection coating for steel construction elements, but also for construction elements made of other materials such as concrete or wood, and as a fire protection coating for individual cables, cable bundles, cable trays and cable ducts or other lines.

The invention therefore also relates to the use of the composition according to the invention as a coating, in particular as a coating of metallic and / or non-metallic substrates, especially for construction elements or components made of steel, concrete, wood and other materials such as plastics, especially as a fire protection coating .

The following examples serve to further illustrate the invention.

EXAMPLES

On the basis of the exemplary embodiments, we show that the use of water-soluble alkali metal silicates can improve the mechanical properties, in particular the mechanical resistance of a coating.

The comparison formulation and formulations according to the invention which can be seen from Table 1 were prepared.

Samples of the compositions were allowed to cure for at least 3 days at about 22 ° C. The mechanical and elastic properties were then assessed using a microhardness measurement in accordance with ISO 14577. A FISCHERSCOPE HM2000S was used for this and the following method was applied: a test force of F = 250 mN was applied to the test specimen over a period of t _incr = 60 s, then held for t _hold = 60 s and then again within t _decr = 60 s relieved. The penetration creep (CIT) and the elastic component of the penetration work (nIT) were used to assess the robustness and resistance to mechanical stress. While CIT is a measure of the yielding when a constant force is applied, nIT provides information about the springback behavior. Here, a smaller plastic deformation means a stronger elastic deformation.

The measured values shown result from the arithmetic mean of five measurements. The measured values obtained were normalized so that the measurements of the comparison formulation were given the value 1.

• Kraft = 250 mN,
• Aufbringzeit t_incr = 60 s,
• Haltezeit t_hold = 60s,
• Entlastungszeit t_decr = 60 s.

Liste der in der Vergleichsformulierung und den erfindungsgemäßen Formulierungen verwendeten Bestandteile: Epilox® F16-01 Epoxidharz auf der Basis von Bisphenol; Viskosität bei 25°C 1200-1600 mPA·s; Epoxidäquivalent 157-167 g/Äqu; Dichte bei 20°C ca. 1,17 g/cm³; Leuna-Harze GmbH Ancamine® K54 Tris-(dimethylaminomethyl)phenol, techn. Grad; EVONIK Industries AG CeTePox® 2200 H Mercaptanterminiertes Polymer, Fa. CTP Chemicals And Technologies for Polymers GmbH Exolit® AP 462 Ammoniumpolyphosphat, mikroverkapselt mit Melamin, Clariant Charmor® PM 40 Pentaerythritol; Fa. Perstop Melafine® Melamin; OCI Melamine Americas Kronos® 2056 Titandioxid; Kronos International, Inc. BYK-W 903 2-Methoxy-1-methylethylacetat; BYK-Chemie GmbH INOCOT K-2837 Kaliumsilikat mit einem Molverhältnis K₂O:SiO₂ = 1 : > 3,20 (40%-ig in Wasser (v/v)); vanBaerle AG. INOSIL XM 35 Kaliumsilikat in Pulverform mit einem Molverhältnis K₂O:SiO₂ = 1 : > 2,6; vanBaerle AG. Tabelle 1: Zusammensetzung der Vergleichsformulierung und der erfindungsgemäßen Formulierungen, sowie die Ergebnisse der Messungen Beispiel Vergleich 1 2 3 4 5 6 Epilox® F 16-01 9,5 g 9,5 g 9,5 g 9,5 g 9,5 g 9,5 g 9,5 g Ancamine® K54 0,5 g 0,5 g 0,5 g 0,5 g 0,5 g 0,5 g 0,5 g CeTePox® 2200 H 15,3 g 15,3 g 15,3 g 15,3 g 15,3 g 15,3 g 15,3 g Exolit® AP 462 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g Charmor® PM 40 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g Melafine® 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g Kronos® 2056 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g 5,0 g BYK-W 903 0,34 g 0,34 g 0,34 g 0,34 g 0,34 g 0,34 g 0,34 g INOCOT K-2837 0,5 g 1,25 g 2,5 g INOSIL XM 35 0,5 g 1,25 g 2,5 g CIT 1,0 0,29 0,20 0,22 0,48 0,45 0,38 nIT 1,0 1,19 1,24 1,24 1,17 1,17 1,19 The test parameters were as follows:

• Force = 250 mN,
• _{Application time} t _incr = 60 s,
• _Hold time t _hold = 60s,
• Relief time t _decr = 60 s.

<u> List of the ingredients used in the comparative formulation and the formulations according to the invention: </u> Epilox® F16-01 Bisphenol-based epoxy resin; Viscosity at 25 ° C 1200-1600 mPa.s; Epoxy equivalent 157-167 g / eq; Density at 20 ° C. approx. 1.17 g / cm ³ ; Leuna-Harze GmbH Ancamine® K54 Tris (dimethylaminomethyl) phenol, techn. Degree; EVONIK Industries AG CeTePox® 2200 H Mercaptan-terminated polymer, CTP Chemicals And Technologies for Polymers GmbH Exolit® AP 462 Ammonium polyphosphate, microencapsulated with melamine, Clariant Charmor® PM 40 Pentaerythritol; Company Perstop Melafine® Melamine; OCI Melamine Americas Kronos® 2056 Titanium dioxide; Kronos International, Inc. BYK-W 903 2-methoxy-1-methylethyl acetate; BYK-Chemie GmbH INOCOT K-2837 Potassium silicate with a molar ratio K ₂ O: SiO ₂ = 1:> 3.20 (40% in water (v / v)); vanBaerle AG. INOSIL XM 35 Potassium silicate in powder form with a molar ratio K ₂ O: SiO ₂ = 1:>2.6; vanBaerle AG. example comparison 1 2 3 4th 5 6th Epilox® F 16-01 9.5 g 9.5 g 9.5 g 9.5 g 9.5 g 9.5 g 9.5 g Ancamine® K54 0.5 g 0.5 g 0.5 g 0.5 g 0.5 g 0.5 g 0.5 g CeTePox® 2200 H 15.3 g 15.3 g 15.3 g 15.3 g 15.3 g 15.3 g 15.3 g Exolit® AP 462 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g Charmor® PM 40 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g Melafine® 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g Kronos® 2056 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g 5.0 g BYK-W 903 0.34 g 0.34 g 0.34 g 0.34 g 0.34 g 0.34 g 0.34 g INOCOT K-2837 0.5 g 1.25 g 2.5 g INOSIL XM 35 0.5 g 1.25 g 2.5 g CIT 1.0 0.29 0.20 0.22 0.48 0.45 0.38 nIT 1.0 1.19 1.24 1.24 1.17 1.17 1.19

As can be seen from Table 1, the potassium silicates were each used in three different amounts, so that the formulations contained different concentrations thereof (1%, 2.5% and 5%).

The table clearly shows the influence of potassium silicates. As can be clearly seen from the CIT value, which in the case of the formulations according to the invention is lower than that of the comparison formulation, the resistance to static mechanical stress increases. As can be clearly seen from the higher nIT values of the formulations according to the invention, the elastic properties of the cured coating increase.

Claims (14)

Intumescent composition comprising an epoxy resin, an acid generator and water-soluble alkali silicates. A composition according to claim 1, wherein the acid generator is a phosphorus, sulfur or boron containing compound which decomposes under the action of heat to produce an acid. The composition of claim 1 or 2, wherein the water-soluble alkali silicate has the formula (I), M ₂ O · nSiO ₂ (I), in which M is an alkali metal and n is a number from 1 to 4. The composition of any preceding claim, wherein the composition further comprises a curing agent for the epoxy resin. The composition of claim 4, wherein the curing agent is an amine-functionalized compound or a thiol-functionalized compound, or a combination thereof. The composition of any preceding claim, wherein the composition further contains a catalyst for the reaction of the epoxy resin with the curing agent. Composition according to any one of the preceding claims, wherein the composition further comprises a carbon source and / or a blowing agent and / or a thermally expandable compound. The composition of any preceding claim, wherein the composition further comprises an ash crust stabilizer. Composition according to one of the preceding claims, wherein the composition further comprises organic and / or inorganic aggregates and / or further additives. Composition according to any one of the preceding claims, wherein the epoxy resin is present in an amount of 3 to 95% by weight based on the total weight of the composition. Composition according to any one of the preceding claims, wherein the hardener is present in an amount of from 5 to 97% by weight based on the total weight of the composition. Composition according to any one of the preceding claims, wherein the acid generator is present in an amount of 35 to 85% by weight based on the total weight of the composition. Use of the composition according to any one of Claims 1 to 12 as a coating. Use according to claim 13 for coating metallic and / or non-metallic substrates.